电力系统稳定器设计方法的研究

发布时间：2018-04-21 13:04

本文选题：电力系统稳定器(PSS) + 相位补偿　；参考：《华北电力大学》2014年硕士论文

【摘要】：随着电力系统规模不断扩大,低频振荡问题日益突出。电力系统稳定器(Power system stabilizer, PSS)作为有效抑制低频振荡的重要措施,在电力系统中广为应用。PSS参数选取的是否恰当,对其效果有很关键的影响。本文重点研究了PSS参数的设计方法。 PSS的传统理论是负阻尼机理,以Philips-Heffron模型为基础,通过为系统增加阻尼提高系统稳定性。理论上,相位滞后角度可通过计算从PSS输入点到暂态电势间传递函数的相位差来确定,实际常用发电机机端电压来代替暂态电势。这能否保证其在各种工况和振荡模式下相位补偿的准确度是值得讨论的。本文推导了机端电压和暂态电势间传递函数,并从以下几方面影响因素进行了讨论：参考电压扰动、状态变量初始值和机械功率扰动,有助于解决现阶段PSS运行存在的问题。有功型PSS结构简单,能较好抑制低频振荡,但其使用需满足机械功率变化相对电气功率变化近似不变的前提。当机械功率有较快速且明显变化时,无功功率会反方向大幅变化,即反调。针对现场运行中还存在的一些反调问题,本文建立了发电机机端电压和机械功率的函数关系,无功功率和机械功率的函数关系,从内在机理上对反调问题进行了分析,并加以实例仿真验证,研究了反调的影响因素,抑制反调的措施。为现场调试和系统的稳定运行提供支持作用。本文从全局优化的角度,提出了一种新型的控制器,对称根轨迹法控制器,从根本上解决了相位补偿PSS存在的暂态电势和机端电压替代不完全一致的问题以及反调问题。之后,为了进一步增加其实际应用可行性,对SRL控制器进行了降维简化控制,只保留与转速对应的分量,舍弃那些不易测量的电磁量对应的分量。通过仿真验证可以看到,基本保证了控制效果,并与相角补偿PSS进行对比,讨论两种方法的镇定效果,说明这种控制器是有效且可实现的。
[Abstract]:With the expansion of power system scale, the problem of low frequency oscillation is becoming more and more prominent. Power system stabilizer (PSSs), as an important measure to suppress low frequency oscillation, is widely used in power system. This paper focuses on the design method of PSS parameters. The traditional theory of PSS is the negative damping mechanism. Based on the Philips-Heffron model, the stability of the system is improved by adding damping to the system. Theoretically, the phase lag angle can be determined by calculating the phase difference between the PSS input point and the transient potential transfer function. In practice, the generator terminal voltage is often used to replace the transient potential. Whether this can guarantee the accuracy of phase compensation under various operating conditions and oscillating modes is worth discussing. In this paper, the transfer function between terminal voltage and transient potential is derived, and the following influencing factors are discussed: reference voltage disturbance, initial value of state variable and mechanical power disturbance, which is helpful to solve the problems existing in PSS operation at present. The active power PSS has a simple structure and can suppress the low frequency oscillation well, but its use needs to satisfy the premise that the mechanical power change is approximately invariant relative to the electrical power change. When the mechanical power changes rapidly and obviously, the reactive power will change significantly in the reverse direction, that is, the reverse modulation. In this paper, the functional relationship between generator terminal voltage and mechanical power, reactive power and mechanical power is established, and the inherent mechanism of inverse regulation is analyzed. An example is given to verify the influence factors and the measures to restrain the reverse modulation. To provide support for field debugging and stable operation of the system. From the point of view of global optimization, a new controller, symmetric root locus controller, is proposed in this paper, which fundamentally solves the problem that the transient potential and terminal voltage substitution of phase compensation PSS are not completely consistent with each other, as well as the inverse adjustment problem. Then, in order to further increase its practical feasibility, the reduced dimension control of SRL controller is carried out, only the components corresponding to the rotational speed are retained, and those components corresponding to the electromagnetic quantities that are difficult to measure are discarded. The simulation results show that the control effect is basically guaranteed, and compared with the phase angle compensated PSS, the stabilization effect of the two methods is discussed, which shows that the controller is effective and feasible.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM712

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